A web shell is a shell-like interface that enables a web server to be remotely accessed, often for the purposes of cyberattacks. A web shell is unique in that a web browser is used to interact with it.A web shell could be programmed in any programming language that is supported on a server. Web shells are most commonly written in the PHP programming language due to the widespread usage of PHP for web applications. However, Active Server Pages, ASP.NET, Python, Perl, Ruby, and Unix shell scripts are also used, although these languages are less commonly used.Using network monitoring tools, an attacker can find vulnerabilities that can potentially allow delivery of a web shell. These vulnerabilities are often present in applications that are run on a web server.An attacker can use a web shell to issue shell commands, perform privilege escalation on the web server, and the ability to upload, delete, download, and execute files to and from the web server.

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